1 / 26

270 likes | 452 Views

Renewable Energy. Solar Hydroelectric Wind Wave. Sun emits EM E at av rate (P)= 3.9 x 10 26 J/s E is spread in all directions in a spherical shape from the sun. The power/m 2 hitting Earth is the Intensity. Insolation = incoming solar radiation. I = power/Area A = 4 p r 2 .

Download Presentation
## Renewable Energy

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Renewable Energy**• Solar • Hydroelectric • Wind • Wave**Sun emits EM E at av rate (P)= 3.9 x 1026 J/sE is spread in**all directions in a spherical shape from the sun.The power/m2 hitting Earth is the Intensity. Insolation = incoming solar radiation. I = power/Area A = 4pr2. r orbit ~ 1.5 x 1011m.on Earth ~ 1380 W/m2. R**Energy at surface is either reflected (scattered) or**absorbed • Amount hitting surface & absorbed varies: Angle of rays (max I when 90o to surface) season, cloud cover, type color of surface…**Renewable Energy Sources**• Solar – thermal & photovoltaic (PV) • Hydroelectric • Wind • Waves**Solar**• Solar Panels Photovoltaic PV Cells • heating only. Produce current**Clip 1:30**Solar PV 1:30 • http://www.youtube.com/watch?v=Sur89b7afso Solar Themal 1:30 Clip 1:30 • http://www.youtube.com/watch?v=64mtITOuXiA**Hydroelectric - Dams**• Falling water spins turbine PE >>KE >> Electric • Can calculate energy • mgh is E of water Mass is also density x volume. • At home look at example Hamper pg 192 – 193.**Clip 2:15**Hydro elec 3 min • http://www.youtube.com/watch?v=wvxUZF4lvGw**Pumper Storage German Version 2.5 min**• http://www.youtube.com/watch?v=GJ7ltJlMY9E**1. Hydro Sample Prb**• The flow rate of water over a dam of height 40-m is 500 L/s. • Find the power generated. • density of water is 1 kg/L or 1000 kg/ m3.**Power = rate E transformed.**• GPE = mgh • P = E/t (each second 500 L of water fall = V/t) • P = mgh/t • Need mass water • D = mass/vol dV = mass sub dV for mass. • P = (dV) gh • t • (1 kg/L) (500 L/s) (10 m/s2) (40 m) • P = 200,000 W**Wind Turbine**• Cylindrical volume of air with velocity v, spins blades. KE air > KE blades> elec E. • Power P, = ½ Arv3. • r = air density • A = area of blade sweeps out. Blade = radius. • v = wind velocity**Can calculate Area circle. KE/s = ½ r (pr2) v3.**Power P, = ½ Arv3. Mass = (r) vol**Wind 1.21 min**• http://www.youtube.com/watch?v=0Kx3qj_oRCchttp://www.youtube.com/watch?v=sLXZkn2W-lk&feature=player_detailpage**2. Wind**• Wind with density of 1.2 kg/m3.goes through a windmill with 1.5m blades with vi = 8m/s. The wind slows to 3 m/s, and density changes to 1.8 kg/m3 after leaving the blades. • Find the max power of the windmill.**The DE from the wind is the work done on the blades.**• Pi – Pf • A = pr2. • P = ½ Arv3. Solve for each speed & density. • (2171 – 171)W = 2000 W.**Wave Poweruses up & down motion of waves (KE>PE)**• Pelamis Oscillating • Hot dog Water column**Power in waves comes from OscillationWave alternate from KE**(falling ) to PE rising • Power per lengthofwavefront P/L = ½ A2rgv. A = amplitude (half height) g ~ 10 m/s2. v = wave velocity**3. Waves. A wave with v = 4.8 m/s and height = 10 m is 2 m**long. Find the power. • A = ampl = 5 m. • r = 1000 kg/m3. • g = 10 m/s2. • P/l = ½ A2rgv. • = ½ (5 m)2(1000)(10)(4.8 m/s) = 6 x 105 W/m • For 2 m wave = 1.2 MW**Oscillating Water Column2:45**• http://www.youtube.com/watch?v=gcStpg3i5V8 Pelamis no sound 2 min http://www.youtube.com/watch?v=mcTNkoyvLFs**Hints.**• Often use density to get a mass. • Must approximate shapes for volume calculation. • Ep = mgh for both hydroelectric & derivation of wave energy. • Rates L/s or kg/s often can be used somehow to get at power which is a rate. • Ex P = mgh = rVgh. V is a flow rate. t t t**Derivation of Equation**• A wave on the surface of water is assumed to be a square-wave of height 2A, as shown. • The wave has wavelength λ, speed v and has a wavefront of length L. For this wave, • (i)show that the gravitational potential energy EP stored in one wavelength of the wave is given by • EP = ½ A2lgρL. • where ρ is the density of the water and g is the acceleration of free fall.**Mass water = rV = r (1/2 AlL).**• Height fall = A • mgh = r (1/2 AlL) A = 1/2A2lrg

More Related